Garrett's Sea Hunter II is one fine PI unit. I used to use one years ago but got older and found it could find targers deeper in the sand than I cared to want to dig. I didn't like it in fresh water even when using the Dscrete Trash Mode as hair pins can last a long time in fresh water unlike salt water where they rust away fast. It will however find many targets deep in the muck. Since muck and silt in fresh water can hold a gold ring at two foot or more, the pulse is the only way to get at them besides dredging the silt to sift for the goodies. Dredging did the job, but I classified that as more like work and not detecting.
But you should enjoy it a lot. I never had any problems with the coil wanting to float like with the White's water detectors. For them you needed to have a weighted sock taped to the shaft to hold it near the bottom. Battery usage seemed to be above average for a pulse unit I thought.
Good Luck,
Sandman